Can you help me with this,
I would like to get the week number of the "Monday",
Say if we run on first week of november it should give me output as "05" and "10" i.e it says the monday falls on 5th week of october.
If we run on the second week of november it should give me "01" and "11".
Says Monday falls on 1st week of november.

I don't really follow you here. But read the date arithmetic article in our FAQ section and look at datecalc, which can probably do whatever it is that you want to do.

datecalc -c 2006 10 1

will return an integer from 0 to 6 to indicate the day of the week for Oct 1, 2006. Once you have the DOW of the first day of a month, subtract that from 9 which will give the the day of the first or second Monday in the month. So if that is larger than 7, subtract 7 from it. Now you are guaranteed to have the day of the month which is the first Monday.